Apparatus for manufacturing water gas



April 3, 1934. o. H. BLACKWOOD ET AL 1,953,061

APPARQTUS FOR MANUFACTURING WATER GAS Filed May 28, 1951 5 Sheets-Sheet1 BY A q? I A 0 EY./

Ap l 3 o. H. BLACKWOOD El AL 1,953,061 APPARATUS FOR MANUFACTURING WATERGAS Filed May 28, 1931 s Sheet-Sheet 2 0sw0 d/2 Sham/00a B Y Paa/ 6ffir/Ina C afcm us/r/o/v 0 asco/yafi area/Y A55 0 5759/? LECO/VFUS/WO/Y00 Y IN VENT 0R5,

April 1934- o. H. BLACKWOOD ET AL 1,953,061

APPARATUS FOR MANUFACTURING WATER GAS Filed May 28, 1931 3 Sheets-Sheet3 Patented Apr. 3, 1934 APPARATUS FOR MANUFACTURING WATER GAS Oswald H.Blackwood and Paul G. Exline, Pittsburgh, Pa.,, assignors' to TheKoppers Company of Delaware,

a corporation of Delaware Application May 28, 1931, Serial No. 540,594

7 Claims.

paratus for the measurement of the water vaporor steam content of thewater-gas output of a water-gas machine. With this object in view,definite portions of the gas being tested are sub-. jected to a'coolingaction for condensing the vapor within a closed space so that the amountof vapor changed to liquid can be made evident by the degree of theensuing vacuum.

Water-gas is made by passing steam through an incandescent fuel bed toform hydrogen and carbon monoxide and the presence of an excess ofmoisture in the gas leaving the fuel bed shows that the temperature ofthe fuel bed is too low.

It is therefore another object to provide a device for regulating theautomatic control of a water gas set with regard to the water vapor orsteam content of the water gas output of the generator.

Further objects are to simplify and improve the construction andoperation of devices of this character, to render them inexpensive tomanufacture, and eificient and convenient in use.

Other objects and features of novelty will be apparent as the followingdescription proceeds, reference being had to the accompanying drawings,in which Figure 1 is an elevational view partly in crosssection of themeasuring apparatus as adapted to water vapor determinations;

Fig. 2 is a similar view of a modification;

Fig. 3 is a calibration curve for the apparatus as used to indicatevapor density;

Fig. 4 is a calibration curve for the apparatus as used to indicatesteam decomposition;

Fig. 5 is a typical steam decomposition curve obtained by the apparatuswhen attached to a water-gas machine;

Fig. 6 is an elevation of the apparatus of Fig. 1 so connected to anautomatic control for a water-gas machine as to control the same; and

Fig. 7 is a more or less diagrammatic elevational view of a water-gasset having an autoa certain amount of vapor will escape through maticcontrol provided with the regulating device of the present invention.

Referring more particularly to the drawings, a relatively large volumeof the warm gas, the vapor content of which is to be determined ispassed through a pipe 1, as shown in Fig. 1, and through a coarse filter2, after which a portion is drawn into the main filter 3, and theremainder discharges through vent pipe 4 to the atmosphere. In this way,the sample drawn into the filter 3 is always drawn against a constanthead. The main filter 3 is heated by electrical current from terminals 5to prevent condensation.

The sample of gas then passes through an orifice controlled by a needlevalve 6, and through a tube or coil 7 of a. condenser 8. Water or othersuitable cooling medium is circulated around the coil 7. Most of thevapor in the gas condenses and collects as liquid in the vessel 9 whichin practice is provided with an outlet trap. A vacuum gauge 10 isconnected to the coil 7. The residual gas from which vapor has beenremoved is drawn out of the apparatus by means of a positivedisplacement or constant volume output pump 11 which is operated at auniform rate of 30 speed.

The operation of the steam measuring apparatus is so conducted that witha given speed of the vacuum pump 11 and a given temperature of thecooling medium in the condenser 8, and with 35 the gas to be testedentirely freed from water vapor a vacuum of preferably five inches ofmercury is maintained. This .is accomplished by proper adjustment of theneedle valve 6 which controls the adjustable orifice. I

Obviously, when the pipe 1 is then connected to the warm gas that is tobe tested, if any steam is contained therein most of it will condense inthe coil 7, leaving a smaller volume of non-condensible gas to beremoved by the pump and the degree of vacuum will be increased. The moresteam present the greater will be the degree of evacuation.

If the temperature of the condenser is not low,

the pump. This need not cause error because it may be taken care ofeither by calibration curves for different condenser temperatures or bydifferent sets of dials for the gauge. The inlet pipe is made reasonablyshort to insure a short equilibrium period.

In the modification shown in Fig. 2, a constant volume inlet device 12takes the place of the orifice controlled by the needle valve 6. Thedevice 12 comprises a three-way cock or valve 13 having a port ofL-shape and'which is rotated at constant speed and alternately places achamber 14 in communication, first with the inlet 1 through a port 15and with the condenser 8 through a port 16.

When the chamber 14 is in communication with the inlet 1 it fills withgas at inlet pressure and when the chamber is in communication with thecondenser coil 7 within the condenser 8 gas passes into the coil and thepressure falls, a vacuum being created by the condensation of vaporwithin the coil and the action of the pump 11 on the gas and vapor thatis not condensed in the coil 7.

Movement of the piston 1'7 adjusts the rate of passing of the gasthrough the inlet device 12 by altering the volume of the chamber 14.Since the through put is directly proportional to the rate of rotationof the valve 13 and to the volume of the chamber 14, the equilibriumpressure for a given vapor content of the gas may be varied by varyingeither the speed of rotation of the valve or the volume of the chamber.

The constant volume inlet 12 is covered with heat insulating material 18to prevent condensation of the vapor being measured. The presence of aheating coil or an electric element as the one supplied with current bythe terminals 5, is of considerable importance as it tends to keep thetemperature of the gas constant.

A pressure regulating valve 19 is shown as forming part of themodification of the apparatus shown in Fig. 2. This is not necessaryexcept in cases where there are large fluctuations in the pressure ofthe gas to be tested. The valve 19 takes the place of the vent pipe 4 ofFig. 1.

The operation of the constant volume inlet with its valve moving atconstant speed is such that it is free from errors due to deviation inthe specific gravity of the gas. That is, its operation is solelydependent on considerations of volume, pressure and temperature. Thepressure difference between the inlet port 15 and the condenser port 16isdependent on the speed of the vacuum pump 11 and the temperature ofthe condenser coil 7, both of which factors are kept constant.

The volume of the chamber 14 is constant except as adjusted by piston 17and the temperature of the gas entering through port 15 should notvary.. Then if the specific gravity of the gases entering through port15 should change due to variation in the proportion of some of theconstituents, exactly the same volume of gas passes through valve 13into the condenser as before, be-' cause the action of the chamber 14 isnot affected by the weight of gas entering and leaving. Moreover thereis no small orifice to become altered in size or closed by particles ofdust.

With the orifice in the needle valve 6 as shown in Fig. 1, the volume ofgas passed is a function of the specific gravity of the gas, otherconditions being equal. Consequently, new settings of the orifice orrevised calibrations must be made when gas of widely different specificgravity is being tested. However, for practical test purposes thevariation in gravity of gas made in any one operation is not sufficientto affect seriously the accuracy of the instrument. Other conditionsbeing the same, the rate of effusion of the gas through an orifice suchas that of Fig. 1 is inversely proportional to the square root of thedensity of the gas.

The calibration curve for vapor is shown in Fig. 3. The ordinatesrepresent inches of mercury, the abscissae, precent of vapor in the gas,and

the single curve is for a condenser temperature of 32 F.

The curve showing the calibration for steam decomposition in a water-gasgenerator is as shown in Fig. 4, wherein the ordinates represent inchesof mercury and the abscissa: percentage of steam decomposition.

The object of the curve is that the readings will express the percentageof input steam decomposed instead of expressing the percentage ofresidual steam remaining in the resultant gas. However, the residualsteam is the factor which produces the vacuum in the apparatus.

In theoretical water-gas consisting of 50% H2 and 50% CO, each twovolumes of gas is a result of the decomposition of one volume of steam,

hence the departure of the curve from a straight line. For example, 50undecomposed or residual steam in the resultant gas corresponds to 33decomposition of the input steam to the bed of fuel since two volumes ofgas result from one volume of steam.

If the steam blown through the fuel bed of the water-gas generatorundergoes decomposition, there is then no steam in the output gas.Consequently, 5 inches of mercury is shown on the gauge indicating thevacuum, because this degree has arbitrarily been selected as one of themost convenient settings for dry gas. If none ofthe steam being blownthrough the fuel bed of the water-gas generator is decomposed, then theoutput gas is all steam so that the maximum vacuum of 29 inches ofmercury is indicated.

The steam decomposition curve in Fig. 5 shows the percentage of steamdecomposition in a typical water-gas plant through the gas-making periodof one cycle and ranges from 80% at the beginning downto about 15% atthe end of 150 seconds. The sudden drop at the end of 55 seconds is dueto the change from up-run to downrun and the sudden drop at the end of150 seconds is due to the change from down-run to up-run.

In Figs. 6 and 7 the apparatus is shown applied to a water-gas set toaid in the control of the same. The inlet or sampling pipe 1 isconnected to the gas offtake pipe 21 leading from a water gas generator20 to a carburetter 22.

The connection leading from the coil '7 of the condenser 8 of thedecomposition apparatus to the pump 11 is provided with a branch pipe 23which leads to two diaphragms 24 and 25 that in turn operate switches 26and 27.

In Figs. 6 and '7 there is shown a water-gas set equipped with anautomatic hydraulic control illustrated and described at length inthepatent to Stone No. 1,671,093, May 22, 1928, and more particularly inthe patent to Stone et al. No. 1,670,911 of May 22, 1928. The timingportion of the automatic control is shown at 28 and this part of themechanism regulates the speed of the automatic hydraulic control througha plurality of small valves 30 during the various portions of the cycleof operations of the water-gas machine.

As set forth and described in the aforesaid patents to Stone and asillustrated 'in Fig. '7, the automatic control is provided with a mastercylinder 40 which is functionally similar to a nest of four-way valves.Hydraulic fluid is supplied under pressure through a conduit 41 to thecylinder 40 which is provided with a drain 42.

The pressure differential between the conduits 41 and 42 is employed togovern the operation of the operating valves of the water gas set, such,for example, as a primary air blast 43, a secondary air blast 44, areversing valve 45, an off-and-on plurality of hydraulic pressure andrelief conduits I 55 to 64 inclusive, pairs of which lead to hydraulicoperating cylinders 65 to 69 inclusive.

By means of the timing mechanism 28, a piston (not shown) travelingwithin the master cylinder 40, is caused to deliver pressure impulses tothe various operatingcylinders 65 to 59 in order to effect operation ofthe various valves 43 to 48 inpredetermined time sequence.

Two of these regulating valves are removed at locations 31 and 32, thesebeing valves that determine the speed of the automatic control duringthe firstuprun and during the downrun respectively. In their stead aresubstituted valves 33 and 34 which normally remain closed and bring theautomatic control to a stop at such times as it,

comes under the control of either of these two valves. The'valves areopened by solenoids 35 and 36 respectively that are in turn connected tothe switches. 26 and 27, the power being derived from a source 3'7.

After either of the valves 33 or 34 has brought the automatic control toa standstill, the watergas set continues in that particular portion ofits cycle until such time as there is a change in the percentage ofsteam decomposition of the gas passing through the ofitake pipe 21, andthis change is detected by the decomposition apparatus through thesample being led off by inlet pipe 1 whereupon through the action ofeither diaphragm 24 or 25 the energizing of solenoids 35 or 36 opensvalve 33 or 34 and allows the automatic control to continue the cycle ofthe water-gas set.

The operation of the decomposition apparatus as applied to anautomatically controlled watergas set as shown in Figs. 6 and 7 is asfollows: The water-gas set operates on a definite cycle that includes anair blasting period in which air passes upwardly through the fuel bed, afirst uprun period during which steam is passed upwardly through thefuel bed, a downrun period in which steam is passed downwardly throughthe fuel bed, and a second steam uprun period.

During the first uprun and during the downrun it is only necessary tomake sufiicient alterations in the automatic control to bring it to astandstill during these two periods. Then it is necessary to install arestarting arrangement under the control of the decomposition apparatusso arranged that when the steam decomposition falls to a certainpercentage during the first uprun or the downrun the automatic controlwill be again started.

In the example illustrated the automatic control is a hydraulic one, anda simple way of stopping this type of automatic control is to insertvalves, such as 33 and 34, in the speed regulating portion of theautomatic control. These valves can readily be opened by solenoids 35and 36 that are energized by current passing through switches 26 and 27that are closed by diaphragms 24 and 25, subject to the vacuum of thecondenser coil 7 of the condenser 8 of the decomposition apparatus.

Each of the plurality of valves 30 in Fig. 6

volumetric capacity regulates the speed of the automatic control d ing adifferent portion of the cycle of the set. Valve 33 when inserted at 31stops the automatic control during the downrun period. Solenoid 35,switch 26 and diaphragm 24 restart the automatic control. Valve 34located at point 32 stops the automatic control during the downrunperiod.

The instrument can be used in a similar manner to control the cycle ofany type of water-gas set other than that shown in Fig. 7, using anyother type of automatic control or any variation of the water-gas set.

In a similar manner it can be used to regulate the rate of supply ofsteam to the generator so as to decrease the rate of steam as thedecomposition tends to decrease. In this way the percentage ofdecomposition can be maintained practically constant throughout thesteaming period.

The measuring apparatus has the advantage of a short time lag or a shortequilibrium period. That is, the interval of time from the startoi achange of moisture content of the gas being sampled until the newreading is indicated on the vacuum gauge is very short, due to the smallof the condenser coil.

The invention can be used to determine moisture content of gas at roomtemperature through the use of liquid, carbon dioxide or other lowtemperature refrigerant. Also the percentage of vapors having muchhigher condensation points than steam can be determined by the use ofsuitable refrigerants.

Other modifications of the measuring apparatus itself are possible. Ithas been found that a pressure pump may be placed at the inlet to thecondenser and the orifice placed to serve as the outlet for thecondenser.

It will be obvious to'those skilled in the art that while I havedescribed my invention with respect to water gas set controllingmechanism of a particular type, namely, the so-called hydraulic control,my invention may be utilized to the same advantage and may be adapted,without requiring anything other than mechanical skill, to water gasinstallations in which the op eration of the set is controlled by meansor other types of automatic controls, for example. mechanical andelectrical controls.

While embodiments of the invention have been illustrated and describedin such detail as to enable anyone skilled in the art to practice theinvention, it is tobe understood that the invention is not to be limitedto the details disclosed, other than as necessitated by the developmentof the prior art. Instead it will be appreciated that the inventionembraces such embodiments of the broad idea as fall within the appendedclaims.

We claim as our invention:

1. In combination, a water gas machine adapted to contain a bed ofcarbonaceous fuel, an automatic control mechanism adapted to operatesaid machine through a series of air-blasting and steaming periods, andmeans responsive to the extent of steam decomposition efiected by saidmachine in said steaming periods for regulating said automatic controlmechanism.

2. In combination, a water gas generating set having valves foradmitting air and steam thereto, an automatic control mechanism foroperating said valves in a predetermined sequence of airblasting andsteaming periods. and an, automatic device for controlling the progressof said control mechanism through said steaming periods 150,

in accordance with the extent of steam decomposition in said periods.

3. In combination, a water gas generating set adapted to contain a bedof carbonaceous fuel, and having valves for admitting air andsteamthereto, an automatic control mechanism for operating said valves in apredetermined sequence of air-blasting and steaming periods, means forarresting the progress of said automatic control mechanism during one ofsaid periods, and means responsive to the extent of steam decompositioneffected by the fuel bed in the steaming periods adapted to release saidautomatic control mechanism;

4. In combination, a Water gas generating set adapted to contain a bedof carbonaceous fuel, and having valves for admitting air and steamthereto, an automatic control mechanism for operating said valves in apredetermined sequence of air-blasting and steaming periods, means forarresting the progress of said automatic control mechanism during saidsteaming periods, and automatic means adapted to release said mechanismwhen the extent of steam decomposition effected by the fuel bed reachesa predetermined point.

5. In combination, a water gas generating set having valves foradmitting air and steam thereto, an automatic control mechanism foroperating said valves in a predetermined sequence of air-blasting andsteaming periods, means for arresting the progress of said automaticcontrol mechanism during one of said periods, means for sampling the gasoutput of said set, means for condensing the steam content of saidsample, and means responsive to pressure change due to said condensationfor releasing said automatic control mechanism.

6. In combination, a water gas generator adapted to contain a bed ofcarbonaceous fuel and having valves for passing air and steam thereto,an automatic hydraulic control mechanism for operating said valves in apredetermined sequence of air-blasting and steaming periods, a normallyclosed valve adapted to interrupt the progress of said mechanism duringone of said steaming periods, and means responsive to the amount ofundecomposed steam in the gas leaving said generator and adapted to opensaid valve when said amount falls to a predetermined value.

7. In combination, a water gas generator adapted to contain a bed ofcarbonaceous fuel, valved means for passing air and steam therethrough,a gas outlet from said generator, a sampling conduit in communicationtherewith, a pump located in said conduit for evacuating gas from saidoutlet, a condenser located in said conduit between the gas outlet fromthe generator and the pump, and means adapted to regulate admission ofsteam to said generator and responsive to the pressure change effectedby said condenser.

OSWALD H. BLACKWOOD. PAUL G. EXLINE.

